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Analysis of Air and Leakage Gas Flows Around CNG Buses with Underslung Gas Cylinders
Technical Paper
2004-28-0037
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SIAT 2004
Language:
English
Abstract
In the drive against air pollution in Delhi, diesel buses were replaced with CNG buses with gas cylinders mounted on the chassis below the bus floor. A series of gas leaks and consequent fire in some buses raised concerns about their fire safety. In this work, leakage flow from a moving bus (2-D, transient) was simulated using a CFD package. As natural gas is lighter than air, buoyancy effects were included. A vertically downward leak in the low pressure system at low speeds causes the gas to move towards the bus front while pushing upwards against the bus floor; a leak in the high pressure system at high vehicle speeds, however, ejects the gas towards the road from where it is convected into the wake. The mixing of natural gas with air was also obtained and regions within flammability limits were identified.
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Citation
Koya, N. and Kale, S., "Analysis of Air and Leakage Gas Flows Around CNG Buses with Underslung Gas Cylinders," SAE Technical Paper 2004-28-0037, 2004, https://doi.org/10.4271/2004-28-0037.Also In
References
- Ota, D. K. Ramakrishnan, S. V. Szema, K. Y. Chakravarthy, S. R. Vitali, D. P. 1993 “Computation of External Automobile Body Shapes” SAE Transactions 2325 2330
- Ono, K. Himeno, R. Fujitani, K. Uematsu, Y. 1992 “Simultaneous Computation of the External Flow Around a Car Body and the Internal Flow Through its Engine Compartment” SAE Transactions 403 411
- George, A. R. Duell, E. G. 1993 “Measurements in the Unsteady Near Wakes of Ground Vehicle Bodies” SAE-Transactions 359 366
- Koromilas, C. Harris, C. Sumantran, V. Pachon, L. Zeng, S. 2000 “Rapid Aerodynamic Development of Two-Volume Vehicle Shapes” SAE Transactions 675 679
- Baysal, O. Bayraktar, I. 2000 “Computational Simulations for the External Aerodynamics of Heavy Trucks” SAE Transactions 813 819
- Saunders, J. W. Watkins, S. Buckley, F. T. Hoffman, P. H. 1985 “Comparison of On-Road and Wind Tunnel tests for Tractor-Trailer Aerodynamic Devices and Fuel Savings Predictions” SAE Transactions 2.702 2.714
- Williams, J. 1985 “An Automotive Front-End Design Approach for Improved Aerodynamics and Cooling” SAE Transactions 2.662 2.684
- Kataoka, T. China, H. Nakagawa, K. Yanagimoto, K. Yoshida, M. 1991 “Numerical Simulation of Road Vehicle Aerodynamics and Effect of Aerodynamic Devices” SAE Transactions 722 734
- Komai, T. Uchida, S. Umezu, M. 1994 “Ignition of Methane-Air Mixture by Frictional Sparks from Light Alloys” Safety Science 17 91 102
- Eckhoff, R. K. Thomassen, O. 1994 “Possible Sources of Ignition of Potential Explosive Gas Atmospheres on Offshore Process Installations” Journal of Loss Prevention 7 281 294
- Lizhong, Y. Weicheng, F. Xiaodong, Z. Quingyan, W. 2001 “Analysis of Fire and Explosion Hazards of some Hydrocarbon-air mixtures” Journal of Hazardous Materials 84 123 131
- Koya. Satyanarayana, N., V., V. 2002 “Analysis of Fluid Flow and Fire Safety in CNG Buses” Mechanical Engineering Department IIT Delhi, India